作者:Steven Coulton、Thomas L. Gilchrist、Keith Graham
DOI:10.1039/a800278i
日期:——
The 8,8a-dihydroazeto[1,2-a]indol-2(1H)-ones (benzocarbapenems) 1a, 16, 17, 22, 27, 35 and 36 have been prepared by cyclodehydration of the corresponding β-amino acids, these amino acids being obtained by reduction of the analogous 2-substituted or 2,7-disubstituted indoles. The hydroxy group of compound 36 is designed to mimic the carboxylic acid function of the carbapenems on the basis of molecular modelling. The azetidinones 1a and 27, which are unsubstituted at the methylene group of the four-membered ring, are unstable and highly susceptible to ring opening by nucleophiles but the compounds 22, 35 and 36 with two methyl substituents at this position are much more stable. The carbonyl stretching frequency in the IR is close to 1770 cm–1 for all the azetidinones except the phenol 36 for which the absorption is at 1735 cm–1. An X-ray crystal structure of compound 36 is reported.
8,8a-二氢氮杂环[1,2-a]吲哚-2(1H)-酮(苯并卡培南)1a、16、17、22、27、35和36是通过环脱水反应制备的,其前体为相应的β-氨基酸,这些氨基酸通过还原相应的2-取代或2,7-双取代吲哚获得。化合物36的羟基设计旨在模拟卡培南的羧酸功能,这是基于分子模型的结果。未取代四元环亚甲基的氮杂环酮1a和27不稳定,易受亲核试剂开环,但在该位置具有两个甲基取代基的化合物22、35和36则更为稳定。除了酚类化合物36的吸收频率在1735 cm–1外,所有氮杂环酮的羰基伸缩频率在红外光谱中都接近1770 cm–1。报告了化合物36的X射线晶体结构。